Transceiver systems in wireless communication networks perform the control functions for directing signals among communicating subscribers, or terminals, as well as communication with external networks. The general operations of a radio transceiver system include receiving radio frequency (RF) signals, converting them to signal data, performing various control and signal processing operations on the signal data, converting the signal data to an RF signal and transmitting the RF signal to the wireless subscriber. Transceiver systems in wireless communications networks include radio base stations and distributed antenna systems (DAS). For the reverse link, or uplink, a terminal transmits the RF signal received by the transceiver system. For the forward link, or downlink, the transceiver system transmits the RF signal to a subscriber, or terminal, in the wireless network. A terminal may be fixed or mobile wireless user equipment unit (UE) and may be a wireless device, cellular phone, personal digital assistant (PDA), personal computer or other device equipped with a wireless modem.
The rapid increase in data (e.g., video) communication and content consumption has led to expansion of wireless communication networks. As a result, the introduction of next generation communication standards (e.g., 3GPP LTE-A, IEEE 802.16m) has led to improved techniques for data processing, such as carrier aggregation (e.g., 100 MHz) with 8×8 MIMO (Multiple-Input, Multiple-Output) and CoMP (Cooperative Multi-Point). This in turn has created the need for radio access networks capable of handling wider bandwidths and an increasing number of antennas. These radio access networks will require a higher numbers of fiber links to connect the base stations to the remote radio units. In addition, it is desirable to provide carrier aggregation with Multiple-Input and Multiple-Output (MIMO) and Co-operative Multipoint (CoMP) techniques to significantly increase spectral efficiency. The implementation of Co-Operative Multi-point techniques requires communication between baseband units and enables load balancing for the communication system.
Modern communication systems require an increasing number of optical or copper ports and links between the baseband units and the radio units to support the various protocols and they often require a large number of discrete devices and signal routing traces to support the improved architectures. However, the improved architectures may not scale due to input and output bottlenecks. The large number of discrete devices and signal routing may also increase the cost of the device. Additionally, innovative device architectures will be required to support the increased clock frequency operation and the larger number of processing functions to efficiently process uplink, feedback and downlink data in addition to the required control signals. To support remote monitoring, debugging, control and management, such devices will also need to support a large amount of data storage.
Accordingly, there is a need for a method and apparatus that will allow for an increasing number of antennas at the radio unit as well as implementation of MIMO, CoMP and load balancing, while reducing power consumption and cost of the device. Also, there is a need for a method and apparatus that will provide these features while reducing the number of discrete devices.